Production of immunized cotton or other cellulosic fibers



Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE I PRODUCTION OFIMDIUNIZED COTTON R OTHER CELLULOSIC FIBERS John Edward Jones, Spondon,near Derby, England, assignor to Celanese Corporation of America, acorporation of Delaware No Drawing. Application December 31, 1931;Serial No. 584,286. In Great Britain February w 1 Claim.

torethe direct cotton dyestufis. The tri-acetate or acetates havingacetyl values between those of diand tri-acetat'e are soluble in organicsolvents and may be employed in the manufacture of cellulose acetateartificial silk. On the other hand, the cellulose acetates having acetylvalues up to and including that corresponding with the di-acetate, oreven slightly higher, and produced by the acetylation of cotton withoutloss of structure, are employed for use as eilect threads in themanufacture of various mixed fabrics. The present invention is concernedwith the manuiactureof effect threads of this type.

According to the present invention, immunized fibers are produced by theesterification of cotton or other cellulosic fibers with the aid ofsulphonic acids ascatalysts. As is alreadyindicated above,

- the esterification will only be partial and may be carried to thepoint monoor di-ester stage or to an intermediate stage or to slightlyabove the di-ester stage. I have found that the sulphonic acids are ofgreat value in obtaining these efi'ect threads without loss of structureof the cotton or other fiber. already been suggested in acetylations tothe triacetate stage, but they have not come into general use for thispurpose. I find that they are admirably adapted for the purpose ofmanufacturing eflect threads.

As examples of suitable sulphonic acids for use in accordance with thepresent invention the fol-- lowing may be instanced, sulpho acetic acid,

- ethylene sulphonic acid, methyl sulphonic acid,

propyl1.2 or 1.3 di-sulphonic acid, sulpho succinic acid, ethanolsulphonic acid, benzyl sulphonic acid, benzene sulphonic acid,para-toluene sulphonic acid, phenol sulphonicacids, phenol disulphonicacid, sulpho salicylic acid, sulpho phthalic acid, naphthalene sulphonicacids and naphthol sulphonic acids. I prefer to employ the Some ofthesulphonic acids have.

tions of petroleum in general, or mixtures thereof. The presentcatalysts are particularly adapted to produce a moderate action capableof being adequately controlledso that the "effect threads only areproduced and the esterification does not proceed to the tri-ester stage.

The fibers treated in accordance with the present invention may becotton, jute, linen or any other natural cellulosic fibenor thecellulosic type 4 of artificial silk, such as viscose, cuprammonium andnitro cellulose artificial silks. They may be treated in the form offilaments, yarns, threads or the like either in the loose or in hankform or in the form of other wound packages, or fabrics made of orcontaining the said fibers may be treated. Local immunized effects maybe obtained by the local application of the esterifying mixture, as forexample by printing methods.

The fiber to be esterified may,-if desired, be pretreated before theactual esterification, as for example by a pretreatment with organicacids as described in French specification No. 565,654, in large orsmall quantities and in the liquid or vapour state (compare U. S. PatentNo. 1,831,101). Again a pretreatment with hydrohalide acids as describedin U. S. applications Nos. 328,306 filed 24th December, 1928, and348,981 filed 21st March, 1929, may be applied, though this is lessadvantageous in the case of the present invention inasmuch as theesteriflcation is to be performed in the presence of sulphonic-acids. Afurther form of pretreatment consists in treating the cotton or otherfiber with the catalyst to be employed in the subsequent esterification,such pretreatment being carried out with or without diluents,

as for example those listed above for the esterifi-- cation itself.Furthermore the cotton may be pretreated with the esterifying agent,for-example an anhydride, before carrying out the main esterification,such pretreatment being applied with the esterifying agent alone ormixed with a diluent as already described, or with the catalyst or withboth. For instance the cotton may be immersed for some time in thecomplete esterification mixture at a temperature insuilicient to causesubstantial esterification, and subsequently the temperature may beraised to effect the esterification proper.

As already indicated the ester content of the products produced inaccordance with the present invention may vary up to the di-ester stageor slightly above. I find that it is particularly advantageous toncarrythe esterification to between the monoand the di-ester stage, forexample in the case of an acetylation to an acetyl agent used.

The following example illustrates the present invention but is not toconsidered as limiting it in any way:-

' Example 100 parts of cotton yarn are immersed in a bath containing 500to 700 parts of acetic acid, 125 to 225 parts of acetic anhydride and toparts of sulpho'acetic acid. The temperature is maintained at about 50C. for A; hour, after which the cotton is removed, washed and dried. Theacetylcontent is about calculated as acetic acid.

In a similar manner other sulphonic acids, for

example those listed above, may be employed.

Again instead oi employing acetic anhydride other aliphatic anhydridesmay be employed, using in general somewhat higher temperatures as thecarbon content of .the acid anhydride increases.

Where as in thecase oi lauric anhydride the acidylating agentis a solidat ordinary temperatures, it may be melted, if feasible, alone or inadmixture with the corresponding acid and the yarn or fabric immersed inthe melted bath containing the catalyst,-or the acidylating agent withor withoutthe corresponding acid may be dissolved in' a suitablediluent, for example a hydrocarbon,and the yamor fabric then immersed inthe bath maintained at a suitable temperature.

What I claim and desire to secure by Letters Patent is:

Process for immunizing cellulosic fibers comprising esterifying the sameat a temperature of about C; to a point not substantially exceeding the(ll-ester stage in the presence of a. sulfonic acid.

JOHN EDWARD JONES.

